The investigators aim to collect data that could provide information about the advantages and disadvantages of the routinely performed 3D CBCT preoperative MMA surgery planning for OSAS patients, regarding 3D volumetric changes of the upper airway and its anatomic subregions and quality of life (QOL) in a subjective manner with the Epworth Sleepiness Scale (ESS) and the OSAS questionnaire and in an objective manner with evaluation of the apnea-hypopnea index (AHI).